Environmental exposures may increase the risk of chronic disease, either directly, or through their interaction with individual characteristics such as hormonal status, immune response, or genetic susceptibility. 1.) Data analysis continues in a study of risk factors for chronic renal disease. In a related pilot study, IgA nephropathy, a possibly immunologically- mediated subgroup of glomerulonephritis, was found to be associated with a previous history of kidney diseases, suggesting the possibility of misclassification of earlier episodes. Alternatively, individuals with previous kidney infections, stones, gout, or acute glomerulonephritis may become more susceptible to reno-toxic or immunologic effects of later exposures. Contrary to expectation, allergies were not associated with IgA nephropathy risk, and an apparent association with frequent colds was found to be due to use of antibiotics rather than colds, per se. Rick for IgA nephropathy was found to be associated with use of artificial sweeteners, especially in carbonated beverages, and with employment in wood products industries, work involving car batteries or radiators, and exposure to turpentine and iron fumes or particles. 2.) A cohort of 1000 women who contributed prospective menstrual and reproductive data since 1935 were traced and interviewed to determine their risk of several diseases. Family history of breast cancer and increased cyclic hormone exposure were associated with increased breast cancer risk. Women with shorter cycles and women with more frequent cycles had the greatest risk of breast cancer. Other well established breast cancer risk factors were confirmed. The risk for other diseases such as colorectal neoplasms and gallbladder disease are being evaluated.